• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.62-73
• /
• 2001

The scope of this study is focused on the survey of new logistics transportation systems in railroad and case studies of new systems such as piggyback system, bi-modal system swapbody, and double stack train(DST). Piggyback system, bi-modal system, swapbody, and double stack train are reviewed in term of technological validity and economic validity in Korea. Piggyback - trailer does pass loaded weight limits but does not pass train limits and can not utilize the existing freight cars. Piggyback - cargo trunk does pass all the criteria and could be developed by a domestic technology. But this study suggests to expand the length of train cars to 18.300mm for accommodation of two cargo trucks. Bi-modal system and swapbody do also pass. Double stack train could only pass the loaded weights and does not meet the train limit and the possibility of using existing freight cars. Domestic technology could not development DST, due to civil engineering construction limits and low standard height of electric line, which could not afford to operate DST.

• Journal of the Speleological Society of Korea
• /
• no.88
• /
• pp.45-50
• /
• 2008

It is rapidly increasing number using Hi-pass system passing through tollgate on the high way. However disabled people and man of merit have been excepted existing advantage of discount when they are using Hi-Pass. It is difficult to make a check an advantage when they are in a vehicle for using Hi-pass system technology in present. For solving this problem, we have fabricated virtual Hi-pass system combined fingerprint identification system (FIS) by AVR and fingerprint identification USB. We checked the chance of efficiency and utility in this system for getting a solution of conservative problem. And, it will be also used for entrance ticketing and transferring of cave tourism and so on.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.1
• /
• pp.7-13
• /
• 2014

In this paper, a novel waveguide low pass filter for satellite communication is proposed. The proposed low pass filter is designed to obtain wideband characteristics without the interference of higher order modes, sufficient attenuation in the stop-band and small sized lightweight characteristics by evanescent-mode ridge structure. To improve return loss and rejection loss, rectangular ring is inserting around the ridges in the waveguide. Input and output ports of the low pass filter is designed by using the impedance step structure for the impedance matching of the filter. The proposed waveguide low pass filter is fabricated and then measured as return loss over 19.5 dB, insertion loss less than 1.41 dB at the pass-band of 7.25 ~ 8.4 GHz and rejection loss over 67.2 dB at the stop-band of 12.25 ~ 14.5 GHz.

• Journal of the Korean Society for information Management
• /
• v.36 no.1
• /
• pp.247-267
• /
• 2019

There has been low use of local information services that public libraries provide, and most of those services are limited only through in-house reading or checkout. Motivated by these issues, the study has developed a mobile application (app, hereafter) entitled as LibPass (a combination of Library and Pass) to propose new local information services that reflect the information needs of users. Regarding the design of LibPass, contents of LibPass are composed of the characteristics of local resources so that users can easily search for information about local culture and tour resources through mobile app. That is, it aims to provide efficient information services on local resources by providing information on accommodations, outdoor programs, and specialized libraries, as well as introducing tour resources. Above all, the services are provided with a single card issued by the National Library of Korea and is convenient to use anywhere in the country. It not only secures reliability and currency by utilizing various contents developed by public institutions, but also provides functions to facilitate specialized services for the local information of libraries. Based on the previous research, the present study derives the factors of quality evaluation of mobile tour information services; it constructs objects of LibPass application by analyzing existing applications and develops the prototype based on logical entity relationship model. This model can contribute to the increased use of local information services and, promotes the public's positive perception of the libraries through user-friendly applications.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.25 no.3
• /
• pp.273-286
• /
• 2017

We develop an inspection method for bearing faults with a rapid change in the rotation speed and present indexes for the pass/fail inspection. At the end of line, impulse noises generated by the operation of machines and conveyors may distort the inspection results. In this paper, we present robust inspection indexes for bearing faults under impulse noises, by taking into account fault signals having pulse train. Using logistic regression, we optimize the pass/fail criterion for each index and evaluate the performance of the inspection indexes based on the total error rate.

• 한국정보통신설비학회:학술대회논문집
• /
• 2003.08a
• /
• pp.293-295
• /
• 2003

In this paper, planar harmonic rejection low-pass filter is proposed to effectively suppress spurious response in stop-band. For suppress the unwanted signal such as spurious and harmonics, we presented a new design method controlled the higher order modes. The proposed low-pass filter was shown to suppress the spurious response by more than $20{\sim}40dB$ compared with conventional microstrip low-pass filters. The filter is evaluated by experiment and simulation with good agreement and shown to have attractive properties such as wide stop band range and low insertion loss.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.642-647
• /
• 2008

The boiler structure is determined by combustion characteristics and construction costs in the combustion chamber of a large commercial boiler. The heat transfer in boiler is composed of the radiation and the convection. The convective heat transfer has happened to back-pass heating surface. The combustion gas sequentially passes through the reheater tube, 1st economizer tube, and 2nd economizer tube. In case of being lowered in boiler height, we have to install additional tube bundle in back-pass heating surface for increasing the heat transfer of boiler, which causes the noise and vibration from combustion gas. When the combustion gas passes through the back-pass tube bundle in specified load of commercial boiler, this paper analyzes the acoustic characteristics between vortex-shedding frequency and natural frequency in tube bundle cavity. The case study reduce the resonance by changing natural frequency characteristics of tube-bundle cavity using a way to install ant-noise baffle in the direction of combustion gas flow.

• Proceedings of the IEEK Conference
• /
• 2000.07a
• /
• pp.207-210
• /
• 2000

This paper introduces a voltage-mode biquadratic circuit using only Operational Amplifiers (OTAs) and Operational Transconductance Amplifiers (OTAs). The proposed circuit can realize low-pass, band-pass, high-pass, band-stop and all-pass transfer functions by suitably choosing the input and output terminals. And the circuit characteristics can be electronically tuned through adjusting the transconductance gains of OTAs. Some examples are given together with simulated results by PSpice. The circuit configuration is very suitable for implementation in both bipolar and CMOS technologies.

• Journal of Korean Institute of Industrial Engineers
• /
• v.6 no.1
• /
• pp.9-15
• /
• 1980

By the mid 1960's the rate of productivity growth in the manufacturing industries of the United States reached the lowest level ever recorded in the American economy. As a result the cost-offsetting operations that had been a century-long part of cost minimizing became less feasible. U.S. manufacturing firins apparently embarked on a pattern of a cost pass-along management. Accounting for price variation as a function of a shift from cost minimizing to cost pass-along is the main subject of this investigation. An econometric model of the inflation process is presented which indicates a clear shift in the modal behavior of manufacturing industries from cost minimizing (1948-1964) to cost pass-along (1965-1975). The latter behavior, initially triggered by the drag of resource diversion on the productivity growth process, undermines the pressure toward productive efficiency that is at the core of industrial engineering, and at the center of U.S. industry's ability to remain competitive.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.7
• /
• pp.998-1000
• /
• 2012

By cascading RHTL (Right-Handed Transmission Line) and LHTL (Left-Handed Transmission Line), we fabricated a BPF (Band Pass Filter) in which the phase propagation at the pass band center frequency is fixed as we want. We utilized a positive phase propagation of a RHTL which is a form of LPF (Low Pass Filter) and negative phase propagation of LHTL which is a form of HPF (High Pass Filter). Therefore, if RHTL and LHTL are cascaded, a BPF can be constructed and the phase propagation inside the passband is decided by the number of RHTLs and LHTLs. In this paper, we provide a detailed theory related to it and proved the theory with an actual experiment. In the experiment, we fabricated two BPFs with similar passband. One with $90^{\circ}$ phase shift and the other with $-90^{\circ}$ phase shift at the center of passband. The result of simulation and actual experiment agrees well. This proves the suggested theory is correct and feasible.